Monitoring of water stress in wheat using multispectral indices derived from Landsat-TM

Abstract

Detection of crop water stress is crucial for efficient irrigation water management. Potential of Satellite data to provide spatial and temporal dynamics of crop growth conditions makes it possible to monitor crop water stress at regional level. This study was conducted in parts of western Uttar Pradesh and Haryana. Multi-temporal Landsat data were used for detecting wheat crop water stress using vegetation indices (VIs), viz. vegetation water stress index (VWSI) and land surface wetness index water stress factor (Ws_LSWI). The estimated water stress from satellite data-based VIs was validated by water stress factor (Ws) derived from flux-tower data. The study observed Ws_LSWI to be better index for water stress detection. The results indicated that Ws_LSWI was superior over other index showing RMSE = 0.12, R² = 0.65, whereas VWSI showed overestimated values with mean RD 4%.

Keywords:

• crop water stress
• vegetation indices
• multi-temporal satellite data

Acknowledgement

Authors sincerely acknowledge Global Land Cover Facility programme of USGS for making Landsat ETM data freely available for this study. We also express sincere gratitude to Dr YVN Krishna Murthy, Director IIRS for providing encouragement, research instrumentation and computational facilities to carry out this study. Authors also sincerely acknowledge Dr VK Dadhwal, Director NRSC for constant support to take up water and carbon flux-related research.

Disclosure statement

No potential conflict of interest was reported by the authors.